Halo 3 - what's your go-to level?

Continuing the trend of the last 2 days. What's your one go-to level you'd pick from Halo 3 if you had time to sit back and play any level?

I suspect I know what the vast majority will pick - The Covenant. And why not? It's probably the most complete level in the game, covering pretty much everything you could want in a single level!

Plus it's a big one story-wise. The Ark runs it close though in second place for me.

What about you?